1. Field of the Invention
The present invention relates to a technique for controlling an earth magnetic field that has a close relation to a picture quality, and more particularly, to an apparatus for automatically controlling directional earth magnetic field which is capable of automatically setting and modifying an strength and a direction of an earth magnetic field, and to its method.
Especially, after earth magnetic field values are stored in a memory unit of a system controller by using an automatic memory function, when an earth magnetic field value to be set as desired by an operator is inputted, an earth magnetic field data corresponding to the earth magnetic field value inputted from the earth magnetic field data stored in the memory unit is read, and by using this data, an output voltage of a power supply unit of an earth magnetic field chamber is variably adjusted so that a desired earth magnetic field value is automatically set or modified.
2. Description of the Background Art
FIG. 1 is a schematic block diagram of an apparatus for controlling an earth magnetic field in accordance with a conventional art, which includes a gauss meter 11 installed in an earth magnetic field chamber, and power supply units 10A, 10B and 10C connected to the gauss meter 11 for respectively supplying a power of three axes X, Y and Z.
The operation and effect of the apparatus for controlling an earth magnetic field in accordance with the conventional art will now be described.
In the conventional earth magnetic field, the operator identifies a numerical value of the gauss meter 11 and manually adjusts a voltage value of the power supply units 10A, 10B and 10C to set a desired earth magnetic field value.
However, since the strength and the direction of the earth magnetic field values are different in every region of the world, the earth magnetic field values need to be set differently at the stage of fabricating a monitor according to the regions where the monitor is to be sold. Thus, in such a conventional art, the operator sets an earth magnetic field value by manually adjusting a voltage value of the power supply units 10A, 10B and 10C while looking up a gauss meter, which has a problem in that the operation time is taken for a long time for setting and modifying the earth magnetic field value, and thus, its productivity is lowered.
Therefore, an object of the present invention is to provide an apparatus for automatically controlling a directional earth magnetic field in which a system controller is set to which a gauss meter is connected through a communication interface, and each of earth magnetic field values measure in the gauss meter is transferred from the system controller through the interface and stored in a memory unit of the system controller, thereby providing an automatic memory function, and, when an earth magnetic field value desired to be set by a user is inputted through a key input, the system controller reads an earth magnetic field data corresponding to the earth magnetic field value inputted form the earth magnetic field data stored in the memory unit, and an output voltage of a power supply unit is adjusted by using the earth magnetic field data, thereby automatically setting the earth magnetic field value of an earth magnetic chamber.
To achieve these and other advantages and in accordance with the purposed of the present invention, as embodied and broadly described herein, there is provided an apparatus for controlling a directional earth magnetic field including a power supply unit 10 for applying a voltage to a coil of an earth magnetic field chamber 50 to generate an earth magnetic field; a system controller 20 for variably controlling the voltage applied to the coil of the earth magnetic field chamber 50 from the power supply unit 10 to automatically set an earth magnetic field value; a key input unit 30 for inputting input information or a command, such as selection of an address and earth magnetic field direction, from a user to the system controller 20; and a screen display unit 40 for displaying an earth magnetic field value set by the system controller 20.
In order to attain the above objects, there is provided a method for automatically controlling directional earth magnetic field including the steps of: positioning a gauss meter at the place where an earth magnetic field is desired to be measured and performing an automatic memory function to receive an earth magnetic field value measured by the gauss meter through a communication interface; giving an address to each earth magnetic field value as transferred and storing it in a memory unit; reading a corresponding earth magnetic field data from the memory unit when an operator inputs an earth magnetic value desired to be set; variably controlling an output voltage of a power supply unit by using the earth magnetic field data as read to automatically set a desired earth magnetic field value.
The earth magnetic field value that has a close relation to the picture quality of a monitor is different in its strength and direction in every region of the world. Thus, the earth magnetic field value is to be set suitable to each region so as to adjust a state of the screen of the monitor, when the monitor is fabricated.
Accordingly, due to the different earth magnetic field values according to regions, the earth magnetic field value is to be modified suitably to regional environment when a production model of the monitor is modified, for which an automatic memory function is provided for automatically setting the strength and the direction of the earth magnetic field of an earth magnetic field chamber that generates an earth magnetic field of a specific region in the present invention.